Wood chair seat drilling machine

ABSTRACT

A wood chair seat drilling machine which can simultaneously drill the leg and spindle holes in opposite sides of the seat.

United States Patent [191 Deeter 1 1 Nov. 12, 1974 WOOD CHAIR SEAT DRILLING MACHINE [56] References Cited [76] Inventor: Richard W. Deeter, 4912 W. Ridge UNITED STATES PATENTS Rd.,E 16506 580.273 4/1897 Grier ..40s/42x [22] Filed: Nov. 7, 1973 Primary E.\'aminerG1| Weldenfeld PP N05 413,642 Attorney, Agent, or FirmRa1ph Hammar [52] US. Cl 408/52, 408/42, 408/101, [57] ABSTRACT 408/103 A wood chair seat drillin h' h' h l V gmac me w 10 can simu ta [51] Irit. Cl B23b 39/16, B23b 41/00 neously driu the leg and Spindk holes in Opposite Sides. [58] Field of Search 408/3, 31, 42, 53, 72, of the seat.

3 Claims, 5 Drawing Figures 1'1 /I4 50 Fill -11! "U 4a n- 42.\ 39 4! -t I 7 43 WOOD CHAIR SEAT DRILLINGMACHINE This invention is intended to increase production and improve accuracy by drilling leg and spindle holes in opposite sides of a wood chair seat blank with the same set up. In the drawing, FIG. 1 is a side elevation of a preferred machine,

FIG. 2 is a front elevation of the machine,

FIG. 3 is a view of one of the drill units in its mounting,

FIG. 4 is a diagrammatic section of the structure for supporting and adjusting one of the drill templates,

FIG. 5 is a diagrammatic view showing structure for locating the drill templates.

The machine has a frame with a base section 1 from opposite ends of which extend laterally spaced pairs of front and back upright members 2, 3. The uprights 2 are tied together by upper and lower cross plates 4 and 5 and similar cross plates tie the uprights 3 together. The upper ends of the uprights 2, 3 are-further tied together by front to back angles 6.

As appears in FIG. 2, the lateral spacing between the uprights 2, 3 is sufficient to receive a template 7 for drilling the leg holes in a chair seat, a template 8 for drilling the spindle holes in a chair seat, and a chair seat blank 9. As shown in FIGS. 1 and 2, the template 7 is of rectangular shape and has upper and lower edges fixed to cross bars 10, 12. The cross bars 10, Marc mounted on adjusting screws 14. The screws 14 are rotated in unison through gearing 16, 17 and a drive shaft 18 rotated by handle 19. The drive shaft 18 is journaled in bearing housings 20 fixed to one of the angles 6. As the crank 19 is turned, the template 7 moves bodily up or down to adjust its vertical position. The template 7 is locked in adjusted position by screws 21 in a vertical adapter plate 11 to which the template is located'by dowels 22. The screws extend through a slot 23 in one of the uprights 2. Tightening the screws 21 locks the plate 11 solidly against the upright so that no movement of the template is possible until the screws are loosened. r

The template 8 is of the same shape as template 7. It is not necessary toadjust the template 8 in order to obtain the correct relation between the leg and spindle holes. Template 8 accordingly may be mounted in fixed relation to the uprights 2, 3. FIG. 5 shows one of the dowels 22 for locating the template 8 and a screw 22a for fastening the template to the upright 3. Similar dow els and screws would be used to locate and fasten the template 7 and other parts of the template 8. In effect, the template 7 is dowelled to a subframe 10, 11, 12 which, after adjustment, is locked to the main frame by tightening screws 21.

The chair seat blank'to be drilled may have been shaped to its finished state as indicated by dotted lines in FIGS. 1 and 2 or it may be a rough blank in which case the blank would have angular edges instead of the curved edges shown. The lower edge of the blank is located by a stop 24 which is vertically adjusted from its lowermost position shown in full lines-by means of adjusting screws 25 screwed into cross plates 5. The stop 24 is shown in dotted lines in position to support the lower edge of the blank 9. The rear edge of the blank is located by a stop 26 adjustably supported by means of studs 27 and nuts 28 on one of the templates 7, 8. The stops 24 and 26 can obviously have different shapes to meet the requirements of other seat blanks.

In the template 7 are moutned four bushings or holders 29 in each of which is fixed the mounting for a self feeding drill unit 30. Thes'elf feeding drill .units are standard commercial products which typically comprise a pneumatic motor 31 driving a drill chuck 32 and a control and feed unit 33. When the unit is actuated, the motor 31 begins to rotate and the bit held by the chuck 32 rapidly advances to the work piece. The length of the rapid advance stroke iscontrolled-by ad- 0 justing nuts 34. At the end of the rapid advance stroke drilling begins at a rate of feed controlled by an adjusting screw 35 and drilling continues until the drilled hole reaches a depth determined by an adjustable positive stop 36. At the end of the stroke, the drill unit rapidly retracts and the motor stops to await another start signal. The drill unit is mounted in the holder 29 by means of a mounting bushing 37 fixed to the drill unitand having a reduced section 3.8 telescoped within .the outer end of the holder and removably fixed to-the holder by a thumb screw 39. Each of the holders 29is fixed'in its template at the proper angle tothe plane of the seat blank 9and each of the drill units is adjusted to. rapidly feed its drill into contact .with the blank, todrill the holes to the correct depth .and then to return the unit I to the start position. The adjustment of the .drill unit and themounting of the holders must take into account the spacing betweenthe blank and the template.

The template 8 is shown as having eight holders 4( each for a drill unit for drilling a spindle hole. Each holder 40 is fixed in the template 8 at the required angle for drilling the hole for its spindle and the drill unit in each holder is adjusted to drill a spindle hole of the required depth.

'The seat blank is clamped in place fordrillingby two pneumatic clamp cylinders 41 on template :8-having pistons 42 which press the blank againststopsAjSgon template 7. V

The number of drill holders and theposition and angular relation of each holder to its template willbe unique to a particular chair seat. Achair manufacturer may have as many as thirty or more differentcombinations of spindle holes andten or moredifferent combinations of leg holes. Any particular chair seat.will,.,accordingly', involve selection of a template 7 fortheleg holes and a template-8 for the spindleholes and this selection will be unique to the particular chair seat. The templates 7 and-.8 are thenmountedbymeans ofdo vels 22 and screws 22aand the relative=position is .adjusted by means of the crank handle 19 and the adjusted position is fixed by tighteningscrews '21. .A drill unit is mounted in each holder 29,40 and each unit is adjusted to drill a hole of the required depth. Tghesto ps 24 and 26 are then adjusted to position the chairseat blank 9. The machine is now setup for operation.

In use, a chair seat'blank 9 is inserted between the templates '7, 8 and positioned by stops 24 and 26. The clamp cylinders 41 are then actuated to clampthechair seat and the drill motors or drill ,units are actuated ,to simultaneously drill the leg and spindleholes-Onceactuated, the drill units simultaneously advance to the chair seat blank, drill .theholes to the-properdepth, and

then retract. The drilled blank may now be remoyedgby is increased by reason of the decreased handling required.

The compressed air supply for the clamps 41 and drill units 30 is conveniently obtained from a tank 44 in the base of the machine.

What is claimed is:

l. A wood chair seat drilling machine comprising 1. a frame having means for supporting a chair seat blank and for supporting first and second templets on opposite sides of the blank,

2. said first template having a first set of holders for drill means presented to one side of the blank, the position and angular relation of the holders being predetermined relative to said first templet and being unique to said one side of the blank,

3. said second template having a second set of holders for drill means presented to the opposite side of said blank, the position and angular relation of the second set of holders being predetermined relative to said second templet and being unique to said opposite side of the blank,

4. means for fixing in each holder a mounting means for a respective one of said drill means, each of said drill means being movable relative to its mounting means to drill a hole of controlled depth, the position and angular relation of the hole relative to the blank being determined by the holder in which the drill means is mounted, 5. means on one of the templates for clamping said blank against stops on the other template to hold the blank while holes are drilled in both sides of the blank.

2. The machine of claim 1 in which the means for clamping the blank comprises a pneumatic cylinder on one of the templates with a piston engaging the blank and clamping the blank against the other template.

3. The machine of claim 1 in which means are provided for adjustably positioning one of the templates, said adjustable positioning means comprising adjusting screws on the frame, mounting means fixed to the template and moved by the screws, a slide on the frame for the mounting means, and means for locking the mounting means to the frame.

l= =l= l= I v 

1. A wood chair seat drilling machine comprising
 1. a frame having means for supporting a chair seat blank and for supporting first and second templets on opposite sides of the blank,
 2. said first template having a first set of holders for drill means presented to one side of the blank, the position and anGular relation of the holders being predetermined relative to said first templet and being unique to said one side of the blank,
 3. said second template having a second set of holders for drill means presented to the opposite side of said blank, the position and angular relation of the second set of holders being predetermined relative to said second templet and being unique to said opposite side of the blank,
 4. means for fixing in each holder a mounting means for a respective one of said drill means, each of said drill means being movable relative to its mounting means to drill a hole of controlled depth, the position and angular relation of the hole relative to the blank being determined by the holder in which the drill means is mounted,
 5. means on one of the templates for clamping said blank against stops on the other template to hold the blank while holes are drilled in both sides of the blank.
 2. said first template having a first set of holders for drill means presented to one side of the blank, the position and anGular relation of the holders being predetermined relative to said first templet and being unique to said one side of the blank,
 2. The machine of claim 1 in which the means for clamping the blank comprises a pneumatic cylinder on one of the templates with a piston engaging the blank and clamping the blank against the other template.
 3. The machine of claim 1 in which means are provided for adjustably positioning one of the templates, said adjustable positioning means comprising adjusting screws on the frame, mounting means fixed to the template and moved by the screws, a slide on the frame for the mounting means, and means for locking the mounting means to the frame.
 3. said second template having a second set of holders for drill means presented to the opposite side of said blank, the position and angular relation of the second set of holders being predetermined relative to said second templet and being unique to said opposite side of the blank,
 4. means for fixing in each holder a mounting means for a respective one of said drill means, each of said drill means being movable relative to its mounting means to drill a hole of controlled depth, the position and angular relation of the hole relative to the blank being determined by the holder in which the drill means is mounted,
 5. means on one of the templates for clamping said blank against stops on the other template to hold the blank while holes are drilled in both sides of the blank. 